1. Field of the Invention
The present invention relates to a carbon fiber structure and a method for manufacturing the same.
2. Description of the Related Art
Since carbon fibers have high heat resistance and strength, they are used as a carbon fiber reinforced carbon composite material (C/C composite material) which includes the carbon fibers and a carbon matrix in various fields requiring heat resistance, chemical stability and strength. The C/C composite material includes various kinds depending upon a compositing method of carbon fibers, and various carbon fiber structures can be formed by using the same.
The C/C composite material is comprised of a matrix made of a carbide such as a pitch or a thermosetting rein, and carbon fibers. There are various C/C composite materials depending upon a fixing method of carbon fibers such as a cloth laminating method using a carbon fiber cloth, a filament winding method using carbon fiber filaments, a method using a carbon fiber felt, and a sheet-forming method using a carbon fiber sheet-formed body.
The cloth laminating method is a method of obtaining a C/C composite material by laminating a woven fabric made of carbon fibers, impregnating the woven fabric with a matrix precursor such as a pitch and a thermosetting resin, followed by curing and calcination (see JP-A-H11-60373). A C/C composite material in a plate form can be obtained by laminating planar woven fabrics and uniaxially pressing the laminate. Also, a C/C composite material in a complicated shape of the papier-mache form can be obtained by sticking small cut woven fabric pieces to a die in a three-dimensional shape. Furthermore, a C/C composite material in a cylindrical shape can also be obtained by a cloth winding method including winding a planar woven fabric in a roll form while applying a pressure thereto and laminating it.
The filament winding method is a method of obtaining a C/C composite material by winding a strand of carbon fibers around a mandrel while applying a tension thereto and then impregnating the wound strand with a matrix precursor such as a pitch and a thermosetting resin, followed by curing and calcination (see JP-A-H10-152391).
The method using a carbon fiber felt is a method of obtaining a C/C composite material by laminating long fibers of carbon fibers in a felt-like form and impregnating the laminate with a matrix precursor such as a pitch and a thermosetting resin, followed by curing and calcination (see JP-A-2000-143360). Similar to the cloth laminating method, according to this method, a planar C/C composite material, a cylindrical C/C composite material and a C/C composite material having a complicated shape can also be obtained. In particular, a cylindrical C/C composite material can also be obtained by sheet winding method including winding up a planar felt in a roll form while applying a pressure thereto, followed by lamination (See, for example, FIGS. 13A and 13B).
Furthermore, in a sheet-forming method, the C/C composite material is obtained by suspending carbon fibers in a liquid to form a slurry, dipping a suction die having an aperture in this slurry, allowing the liquid in the slurry to pass into a rear surface of the suction die and depositing carbon fibers on the surface side of this suction die to form a molded material, following by drying and calcination (see JP-A-2002-68851 and JP-A-2002-97082).
The disclosures of JP-A-H11-60373, JP-A-H10-152391, JP-A-2000-143360, JP-A-2002-68851 and JP-A-2002-97082 are incorporated herein by reference.